SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb06d8f669d841f9e8c655660ed02bc43c2b79a769a2ebc030503d84f41c6b17' 
  AND token = 'REBdzDYtnLrCi7E3JPXe+X1ig+8pvfsF8gsTsvjr0PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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