SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df1a0377abf77c24554e2c5518f5f16725d8838f713fef070b3ecce3cf244251' 
  AND token = '8CEfZ2itXZHX3jg2XeEeIMC9SS95nFKkBeO6AKJ9ekQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}