SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98be358beade47a098695fe866c5757fbb2e4bfa20c9be24dc1af18e6361ee62' 
  AND token = 'pA/Y6F04GjQjEsaukLHrRKYDRwJNzLN0hgF8rRo2q5c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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