SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95c7c5cf0a8662e755b1c591eceaabe0d6fcbb887c76c96b0d6f2042ba92c0b5' 
  AND token = 'nGKiPCox2XSVAKr+bcAv3eGXa/2Zs1GCe6wLQ5s6V2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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