SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eda75eac9a032ff838c3bfb51e8e7656173b57d0356b147cb7387e216280edeb' 
  AND token = 'HqmpOQ6L/MkfNH53dzIx4A4h48j9o+TJzmWrWUEoLy0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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