SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7ae24a6b99738e12d91bee38cbdee6e7dd6b00bd143912bdc16821c5891b3ca' 
  AND token = 'FsedFvegEPmEqIi22iN/NdV5BceE7bzfxuczlgLMpRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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