SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f828814fc3de1043a63cdd4f68db75adcc1177da14d29f6eb8baee7522a1004c' 
  AND token = 'KcGDu7XbRQho/nKEjIagKYWIP/KsILTd4BiRVKB2Jl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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