SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0d287f51e84847c4b5b5c3f45506620b8be1bcf087405a833fb4e50d7032ef2' 
  AND token = 'jm2fRCJLbFHUL3scnnR8hJEt2wbsBPCbxJuOujpqQ68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}