SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edaee842cc2dd253b245d5e1de6dcc7ad9f2a7af2029d468addcddd4d9dbfd43' 
  AND token = 'Ib+BcWFN1rA2hkI1dElqTjdKRwTCAyd79SuzpuJNHpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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