SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc573ecd6800a643eb643f3e9ab86a074b422905884f0c655ef971f2c80c850e' 
  AND token = 'ABdC1E4AfVPO9Dufl7zkjAI6YwnsaKmb/wG+mFOGpzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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