SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58b88baafc94dfebdd3fb1642a6078a6566f524558031bedd9958ce296992869' 
  AND token = 'HVj5IAuCCa4K9mZOgsoWaTGCKPEzeJ/Sx3qshb/4Ncw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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