SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4aa2371ecd0a68a0a2c7fc45eb6d618fba50d83e30050ad2d8ce9ed4bc306288' 
  AND token = '7ILURZkoAaqRbeyudpLfTHCvZlxZ7CFNkFgBL5klZLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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