SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f76289faf2c26fb89e90f04a0626d66fce56d6e711ee204873795a4ffcede73e' 
  AND token = 'jJcTOLrwl1OssCTIbPIAs/kn3ubA14fN/OhOMRfzodY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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