SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0087725d8864805ecfd563c5ef9853febf10468764164a41809d3c389ed7aa2a' 
  AND token = '57TY2WOxGVL5OSigU4D+mb+ZxdXgG7BPJKYEddP6+q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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